Method and apparatus for entering a connected state with a network for continuing transmission in wireless communication system

ABSTRACT

A method and an apparatus for entering a connected state with a network for continuing transmission in a wireless communication system is provided. The method may include starting a Time Alignment Timer (TAT). The method may include leaving a connected state with a network. The method may include performing transmission with a configured grant, wherein the configured grant is received from the network, while in leaving the connected state. The method may include performing a random access (RA) to the network, after the TAT is expired.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage filing under 35 U.S.C. 371 of International Application No. PCT/KR2019/012443, filed on Sep. 25, 2019, which claims the benefit of earlier filing date and right of priority to Korean Patent Application No. 10-2018-0115546 filed on Sep. 28, 2018, the contents of which is hereby incorporated by reference herein in its entirety.

BACKGROUND Technical Field

The present disclosure relates to a method and apparatus for entering a connected state with a network for continuing transmission.

Related Art

3rd generation partnership project (3GPP) long-term evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.

Work has started in international telecommunication union (ITU) and 3GPP to develop requirements and specifications for new radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU radio communication sector (ITU-R) international mobile telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced mobile broadband (eMBB), massive machine-type-communications (mMTC), ultra-reliable and low latency communications (URLLC), etc. The NR shall be inherently forward compatible.

In Rel-13, narrowband internet-of-things (NB-IoT) and LTE for machine-type communication (LTE-M) were standardized to provide wide-area connectivity for IoT. The technologies in Rel-14 evolved beyond the basic functionality specified in Rel-13. In Rel-15, to optimize the support for infrequent small data packet transmissions.

A mechanism for transmission of a wireless device while in leaving a connected has been studied. A wireless device may use a configured grant for transmission. This mechanism could improve the device battery life and reduce the resource for transmission.

SUMMARY

A wireless device may transmit data while in leaving a connected state with a network using pre-allocated resource. However, when the pre-allocated resource is not valid and/or uplink timing is not aligned with the network, a wireless device could not transmit uplink data using the pre-allocated resource. Therefore, a method for entering a connected state with the network for continuing transmission in wireless communication system is required.

In an aspect, a method performed by a wireless device in a wireless communication system is provided. The method may include starting a Time Alignment Timer (TAT). The method may include leaving a connected state with a network. The method may include performing transmission with a configured grant, wherein the configured grant is received from the network, while in leaving the connected state. The method may include performing a random access (RA) to the network, after the TAT is expired.

In another aspect, a wireless device in a wireless communication system is provided. The wireless device may include a memory, a transceiver, and a processor, operably coupled to the memory and the transceiver. The processor may be configured to start a Time Alignment Timer (TAT). The processor may be configured to leave a connected state with a network. The processor may be configured to perform transmission with a configured grant, wherein the configured grant is received from the network, while the wireless device leaves the connected state. The processor may be configured to perform a random access (RA) to the network, after the TAT is expired.

The present disclosure can have various advantageous effects.

According to some embodiments of the present disclosure, a wireless device may continue to transmit data while in leaving a connected state with a network, efficiently.

For example, according to some embodiments of the present disclosure, a wireless device may enter a connected state with a network, when data becomes available and a pre-allocated resource cannot be used.

For example, according to some embodiments of the present disclosure, a wireless device may enter a connected state with a network, when data becomes available and uplink timing is not aligned with the network.

For example, according to some embodiments of the present disclosure, a wireless device may continue data transmission by reconfiguring resource for transmission and/or aligning UL timing with the network in a connected state.

Advantageous effects which can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art can understand and/or derive from the present disclosure. Accordingly, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that may be understood or derived from the technical features of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows examples of 5G usage scenarios to which the technical features of the present disclosure can be applied.

FIG. 2 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 3 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 4 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

FIG. 5 shows a block diagram of a user plane protocol stack to which the technical features of the present disclosure can be applied.

FIG. 6 shows a block diagram of a control plane protocol stack to which the technical features of the present disclosure can be applied.

FIG. 7 shows an example of a connection resume procedure to which the technical features of the present disclosure can be applied.

FIG. 8 shows an example of a method for entering a connected state with a network for continuing transmission, according to some embodiments of the present disclosure.

FIG. 9 shows a flow chart of an example of a method for entering a connected state with a network for continuing transmission, according to some embodiments of the present disclosure.

FIG. 10 shows a method for entering a connected state with a network for continuing data transmission, according to some embodiments of the present disclosure.

FIG. 11 shows an apparatus for entering a connected state with a network after a TAT is expired, according to some embodiments of the present disclosure.

FIG. 12 shows an example of an AI device to which the technical features of the present disclosure can be applied.

FIG. 13 shows an example of an AI system to which the technical features of the present disclosure can be applied.

DESCRIPTION

The technical features described below may be used by a communication standard by the 3rd generation partnership project (3GPP) standardization organization, a communication standard by the institute of electrical and electronics engineers (IEEE), etc. For example, the communication standards by the 3GPP standardization organization include long-term evolution (LTE) and/or evolution of LTE systems. The evolution of LTE systems includes LTE-advanced (LTE-A), LTE-A Pro, and/or 5G new radio (NR). The communication standard by the IEEE standardization organization includes a wireless local area network (WLAN) system such as IEEE 802.11a/b/g/n/ac/ax. The above system uses various multiple access technologies such as orthogonal frequency division multiple access (OFDMA) and/or single carrier frequency division multiple access (SC-FDMA) for downlink (DL) and/or uplink (UL). For example, only OFDMA may be used for DL and only SC-FDMA may be used for UL. Alternatively, OFDMA and SC-FDMA may be used for DL and/or UL.

In this document, the term “/” and “,” should be interpreted to indicate “and/or.” For instance, the expression “A/B” may mean “A and/or B.” Further, “A, B” may mean “A and/or B.” Further, “A/B/C” may mean “at least one of A, B, and/or C.” Also, “A, B, C” may mean “at least one of A, B, and/or C.”

Further, in the document, the term “or” should be interpreted to indicate “and/or.” For instance, the expression “A or B” may comprise 1) only A, 2) only B, and/or 3) both A and B. In other words, the term “or” in this document should be interpreted to indicate “additionally or alternatively.”

FIG. 1 shows examples of 5G usage scenarios to which the technical features of the present disclosure can be applied.

The 5G usage scenarios shown in FIG. 1 are only exemplary, and the technical features of the present disclosure can be applied to other 5G usage scenarios which are not shown in FIG. 1.

Referring to FIG. 1, the three main requirements areas of 5G include (1) enhanced mobile broadband (eMBB) domain, (2) massive machine type communication (mMTC) area, and (3) ultra-reliable and low latency communications (URLLC) area. Some use cases may require multiple areas for optimization and, other use cases may only focus on only one key performance indicator (KPI). 5G is to support these various use cases in a flexible and reliable way.

eMBB focuses on across-the-board enhancements to the data rate, latency, user density, capacity and coverage of mobile broadband access. The eMBB aims ˜10 Gbps of throughput. eMBB far surpasses basic mobile Internet access and covers rich interactive work and media and entertainment applications in cloud and/or augmented reality. Data is one of the key drivers of 5G and may not be able to see dedicated voice services for the first time in the 5G era. In 5G, the voice is expected to be processed as an application simply using the data connection provided by the communication system. The main reason for the increased volume of traffic is an increase in the size of the content and an increase in the number of applications requiring high data rates. Streaming services (audio and video), interactive video and mobile Internet connectivity will become more common as more devices connect to the Internet. Many of these applications require always-on connectivity to push real-time information and notifications to the user. Cloud storage and applications are growing rapidly in mobile communication platforms, which can be applied to both work and entertainment. Cloud storage is a special use case that drives growth of uplink data rate. 5G is also used for remote tasks on the cloud and requires much lower end-to-end delay to maintain a good user experience when the tactile interface is used. In entertainment, for example, cloud games and video streaming are another key factor that increases the demand for mobile broadband capabilities. Entertainment is essential in smartphones and tablets anywhere, including high mobility environments such as trains, cars and airplanes. Another use case is augmented reality and information retrieval for entertainment. Here, augmented reality requires very low latency and instantaneous data amount.

mMTC is designed to enable communication between devices that are low-cost, massive in number and battery-driven, intended to support applications such as smart metering, logistics, and field and body sensors. mMTC aims ˜10 years on battery and/or ˜1 million devices/km2. mMTC allows seamless integration of embedded sensors in all areas and is one of the most widely used 5G applications. Potentially by 2020, internet-of-things (IoT) devices are expected to reach 20.4 billion. Industrial IoT is one of the areas where 5G plays a key role in enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructures.

URLLC will make it possible for devices and machines to communicate with ultra-reliability, very low latency and high availability, making it ideal for vehicular communication, industrial control, factory automation, remote surgery, smart grids and public safety applications. URLLC aims ˜1 ms of latency. URLLC includes new services that will change the industry through links with ultra-reliability/low latency, such as remote control of key infrastructure and self-driving vehicles. The level of reliability and latency is essential for smart grid control, industrial automation, robotics, drones control and coordination.

Next, a plurality of use cases included in the triangle of FIG. 1 will be described in more detail.

5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) as a means of delivering streams rated from hundreds of megabits per second to gigabits per second. This high speed can be required to deliver TVs with resolutions of 4K or more (6K, 8K and above) as well as virtual reality (VR) and augmented reality (AR). VR and AR applications include mostly immersive sporting events. Certain applications may require special network settings. For example, in the case of a VR game, a game company may need to integrate a core server with an edge network server of a network operator to minimize delay.

Automotive is expected to become an important new driver for 5G, with many use cases for mobile communications to vehicles. For example, entertainment for passengers demands high capacity and high mobile broadband at the same time. This is because future users will continue to expect high-quality connections regardless of their location and speed. Another use case in the automotive sector is an augmented reality dashboard. The driver can identify an object in the dark on top of what is being viewed through the front window through the augmented reality dashboard. The augmented reality dashboard displays information that will inform the driver about the object's distance and movement. In the future, the wireless module enables communication between vehicles, information exchange between the vehicle and the supporting infrastructure, and information exchange between the vehicle and other connected devices (e.g. devices accompanied by a pedestrian). The safety system allows the driver to guide the alternative course of action so that he can drive more safely, thereby reducing the risk of accidents. The next step will be a remotely controlled vehicle or self-driving vehicle. This requires a very reliable and very fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, a self-driving vehicle will perform all driving activities, and the driver will focus only on traffic that the vehicle itself cannot identify. The technical requirements of self-driving vehicles require ultra-low latency and high-speed reliability to increase traffic safety to a level not achievable by humans.

Smart cities and smart homes, which are referred to as smart societies, will be embedded in high density wireless sensor networks. The distributed network of intelligent sensors will identify conditions for cost and energy-efficient maintenance of a city or house. A similar setting can be performed for each home. Temperature sensors, windows and heating controllers, burglar alarms and appliances are all wirelessly connected. Many of these sensors typically require low data rate, low power and low cost. However, for example, real-time high-definition (HD) video may be required for certain types of devices for monitoring.

The consumption and distribution of energy, including heat or gas, is highly dispersed, requiring automated control of distributed sensor networks. The smart grid interconnects these sensors using digital information and communication technologies to collect and act on information. This information can include supplier and consumer behavior, allowing the smart grid to improve the distribution of fuel, such as electricity, in terms of efficiency, reliability, economy, production sustainability, and automated methods. The smart grid can be viewed as another sensor network with low latency.

The health sector has many applications that can benefit from mobile communications. Communication systems can support telemedicine to provide clinical care in remote locations. This can help to reduce barriers to distance and improve access to health services that are not continuously available in distant rural areas. It is also used to save lives in critical care and emergency situations. Mobile communication based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring costs are high for installation and maintenance. Thus, the possibility of replacing a cable with a wireless link that can be reconfigured is an attractive opportunity in many industries. However, achieving this requires that wireless connections operate with similar delay, reliability, and capacity as cables and that their management is simplified. Low latency and very low error probabilities are new requirements that need to be connected to 5G.

Logistics and freight tracking are important use cases of mobile communications that enable tracking of inventory and packages anywhere using location based information systems. Use cases of logistics and freight tracking typically require low data rates, but require a large range and reliable location information.

FIG. 2 shows an example of a wireless communication system to which the technical features of the present disclosure can be applied.

Referring to FIG. 2, the wireless communication system may include a first device 210 and a second device 220.

The first device 210 includes a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone, an unmanned aerial vehicle (UAV), an artificial intelligence (AI) module, a robot, an AR device, a VR device, a mixed reality (MR) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fin-tech device (or, a financial device), a security device, a climate/environmental device, a device related to 5G services, or a device related to the fourth industrial revolution.

The second device 220 includes a base station, a network node, a transmitting UE, a receiving UE, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone, a UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fin-tech device (or, a financial device), a security device, a climate/environmental device, a device related to 5G services, or a device related to the fourth industrial revolution.

For example, the UE may include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device, a slate personal computer (PC), a tablet PC, an ultrabook, a wearable device (e.g. a smartwatch, a smart glass, a head mounted display (HMD)). For example, the HMD may be a display device worn on the head. For example, the HMD may be used to implement AR, VR and/or MR.

For example, the drone may be a flying object that is flying by a radio control signal without a person boarding it. For example, the VR device may include a device that implements an object or background in the virtual world. For example, the AR device may include a device that implements connection of an object and/or a background of a virtual world to an object and/or a background of the real world. For example, the MR device may include a device that implements fusion of an object and/or a background of a virtual world to an object and/or a background of the real world. For example, the hologram device may include a device that implements a 360-degree stereoscopic image by recording and playing stereoscopic information by utilizing a phenomenon of interference of light generated by the two laser lights meeting with each other, called holography. For example, the public safety device may include a video relay device or a video device that can be worn by the user's body. For example, the MTC device and the IoT device may be a device that do not require direct human intervention or manipulation. For example, the MTC device and the IoT device may include a smart meter, a vending machine, a thermometer, a smart bulb, a door lock and/or various sensors. For example, the medical device may be a device used for the purpose of diagnosing, treating, alleviating, handling, or preventing a disease. For example, the medical device may be a device used for the purpose of diagnosing, treating, alleviating, or correcting an injury or disorder. For example, the medical device may be a device used for the purpose of inspecting, replacing or modifying a structure or function. For example, the medical device may be a device used for the purpose of controlling pregnancy. For example, the medical device may include a treatment device, a surgical device, an (in vitro) diagnostic device, a hearing aid and/or a procedural device, etc. For example, a security device may be a device installed to prevent the risk that may occur and to maintain safety. For example, the security device may include a camera, a closed-circuit TV (CCTV), a recorder, or a black box. For example, the fin-tech device may be a device capable of providing financial services such as mobile payment. For example, the fin-tech device may include a payment device or a point of sales (POS). For example, the climate/environmental device may include a device for monitoring or predicting the climate/environment.

The first device 210 may include at least one or more processors, such as a processor 211, at least one memory, such as a memory 212, and at least one transceiver, such as a transceiver 213. The processor 211 may perform the functions, procedures, and/or methods of the present disclosure described below. The processor 211 may perform one or more protocols. For example, the processor 211 may perform one or more layers of the air interface protocol. The memory 212 is connected to the processor 211 and may store various types of information and/or instructions. The transceiver 213 is connected to the processor 211 and may be controlled to transmit and receive wireless signals.

The second device 220 may include at least one or more processors, such as a processor 221, at least one memory, such as a memory 222, and at least one transceiver, such as a transceiver 223. The processor 221 may perform the functions, procedures, and/or methods of the present disclosure described below. The processor 221 may perform one or more protocols. For example, the processor 221 may perform one or more layers of the air interface protocol. The memory 222 is connected to the processor 221 and may store various types of information and/or instructions. The transceiver 223 is connected to the processor 221 and may be controlled to transmit and receive wireless signals.

The memory 212, 222 may be connected internally or externally to the processor 211, 221, or may be connected to other processors via a variety of technologies such as wired or wireless connections.

The first device 210 and/or the second device 220 may have more than one antenna. For example, antenna 214 and/or antenna 224 may be configured to transmit and receive wireless signals.

FIG. 3 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

Specifically, FIG. 3 shows a system architecture based on an evolved-UMTS terrestrial radio access network (E-UTRAN). The aforementioned LTE is a part of an evolved-UTMS (e-UMTS) using the E-UTRAN.

Referring to FIG. 3, the wireless communication system includes one or more user equipment (UE) 310, an E-UTRAN and an evolved packet core (EPC). The UE 310 refers to a communication equipment carried by a user. The UE 310 may be fixed or mobile. The UE 310 may be referred to as another terminology, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), and a wireless device, etc.

The E-UTRAN consists of one or more evolved NodeB (eNB) 320. The eNB 320 provides the E-UTRA user plane and control plane protocol terminations towards the UE 10. The eNB 320 is generally a fixed station that communicates with the UE 310. The eNB 320 hosts the functions, such as inter-cell radio resource management (RRM), radio bearer (RB) control, connection mobility control, radio admission control, measurement configuration/provision, dynamic resource allocation (scheduler), etc. The eNB 320 may be referred to as another terminology, such as a base station (BS), a base transceiver system (BTS), an access point (AP), etc.

A downlink (DL) denotes communication from the eNB 320 to the UE 310. An uplink (UL) denotes communication from the UE 310 to the eNB 320. A sidelink (SL) denotes communication between the UEs 310. In the DL, a transmitter may be a part of the eNB 320, and a receiver may be a part of the UE 310. In the UL, the transmitter may be a part of the UE 310, and the receiver may be a part of the eNB 320. In the SL, the transmitter and receiver may be a part of the UE 310.

The EPC includes a mobility management entity (MME), a serving gateway (S-GW) and a packet data network (PDN) gateway (P-GW). The MME hosts the functions, such as non-access stratum (NAS) security, idle state mobility handling, evolved packet system (EPS) bearer control, etc. The S-GW hosts the functions, such as mobility anchoring, etc. The S-GW is a gateway having an E-UTRAN as an endpoint. For convenience, MME/S-GW 330 will be referred to herein simply as a “gateway,” but it is understood that this entity includes both the MME and S-GW. The P-GW hosts the functions, such as UE Internet protocol (IP) address allocation, packet filtering, etc. The P-GW is a gateway having a PDN as an endpoint. The P-GW is connected to an external network.

The UE 310 is connected to the eNB 320 by means of the Uu interface. The UEs 310 are interconnected with each other by means of the PC5 interface. The eNBs 320 are interconnected with each other by means of the X2 interface. The eNBs 320 are also connected by means of the S1 interface to the EPC, more specifically to the MME by means of the S1-MME interface and to the S-GW by means of the S1-U interface. The S1 interface supports a many-to-many relation between MMEs/S-GWs and eNBs.

FIG. 4 shows another example of a wireless communication system to which the technical features of the present disclosure can be applied.

Specifically, FIG. 4 shows a system architecture based on a 5G NR. The entity used in the 5G NR (hereinafter, simply referred to as “NW”) may absorb some or all of the functions of the entities introduced in FIG. 3 (e.g. eNB, MME, S-GW). The entity used in the NR may be identified by the name “NG” for distinction from the LTE/LTE-A.

Referring to FIG. 4, the wireless communication system includes one or more UE 410, a next-generation RAN (NG-RAN) and a 5th generation core network (5GC). The NG-RAN consists of at least one NG-RAN node. The NG-RAN node is an entity corresponding to the eNB 320 shown in FIG. 3. The NG-RAN node consists of at least one gNB 421 and/or at least one ng-eNB 422. The gNB 421 provides NR user plane and control plane protocol terminations towards the UE 410. The ng-eNB 422 provides E-UTRA user plane and control plane protocol terminations towards the UE 410.

The 5GC includes an access and mobility management function (AMF), a user plane function (UPF) and a session management function (SMF). The AMF hosts the functions, such as NAS security, idle state mobility handling, etc. The AMF is an entity including the functions of the conventional MME. The UPF hosts the functions, such as mobility anchoring, protocol data unit (PDU) handling. The UPF an entity including the functions of the conventional 5-GW. The SMF hosts the functions, such as UE IP address allocation, PDU session control.

The gNBs 421 and ng-eNBs 422 are interconnected with each other by means of the Xn interface. The gNBs 421 and ng-eNBs 422 are also connected by means of the NG interfaces to the 5GC, more specifically to the AMF by means of the NG-C interface and to the UPF by means of the NG-U interface.

A protocol structure between network entities described above is described. On the system of FIG. 3 and/or FIG. 4, layers of a radio interface protocol between the UE and the network (e.g. NG-RAN and/or E-UTRAN) may be classified into a first layer (L1), a second layer (L2), and a third layer (L3) based on the lower three layers of the open system interconnection (OSI) model that is well-known in the communication system.

FIG. 5 shows a block diagram of a user plane protocol stack to which the technical features of the present disclosure can be applied. FIG. 6 shows a block diagram of a control plane protocol stack to which the technical features of the present disclosure can be applied.

The user/control plane protocol stacks shown in FIG. 5 and FIG. 6 are used in NR. However, user/control plane protocol stacks shown in FIG. 5 and FIG. 6 may be used in LTE/LTE-A without loss of generality, by replacing gNB/AMF with eNB/MME.

Referring to FIG. 5 and FIG. 6, a physical (PHY) layer belonging to L1. The PHY layer offers information transfer services to media access control (MAC) sublayer and higher layers. The PHY layer offers to the MAC sublayer transport channels. Data between the MAC sublayer and the PHY layer is transferred via the transport channels. Between different PHY layers, i.e., between a PHY layer of a transmission side and a PHY layer of a reception side, data is transferred via the physical channels.

The MAC sublayer belongs to L2. The main services and functions of the MAC sublayer include mapping between logical channels and transport channels, multiplexing/de-multiplexing of MAC service data units (SDUs) belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), priority handling between UEs by means of dynamic scheduling, priority handling between logical channels of one UE by means of logical channel prioritization (LCP), etc. The MAC sublayer offers to the radio link control (RLC) sublayer logical channels.

The RLC sublayer belong to L2. The RLC sublayer supports three transmission modes, i.e. transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM), in order to guarantee various quality of services (QoS) required by radio bearers. The main services and functions of the RLC sublayer depend on the transmission mode. For example, the RLC sublayer provides transfer of upper layer PDUs for all three modes, but provides error correction through ARQ for AM only. In LTE/LTE-A, the RLC sublayer provides concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer) and re-segmentation of RLC data PDUs (only for AM data transfer). In NR, the RLC sublayer provides segmentation (only for AM and UM) and re-segmentation (only for AM) of RLC SDUs and reassembly of SDU (only for AM and UM). That is, the NR does not support concatenation of RLC SDUs. The RLC sublayer offers to the packet data convergence protocol (PDCP) sublayer RLC channels.

The PDCP sublayer belong to L2. The main services and functions of the PDCP sublayer for the user plane include header compression and decompression, transfer of user data, duplicate detection, PDCP PDU routing, retransmission of PDCP SDUs, ciphering and deciphering, etc. The main services and functions of the PDCP sublayer for the control plane include ciphering and integrity protection, transfer of control plane data, etc.

The service data adaptation protocol (SDAP) sublayer belong to L2. The SDAP sublayer is only defined in the user plane. The SDAP sublayer is only defined for NR. The main services and functions of SDAP include, mapping between a QoS flow and a data radio bearer (DRB), and marking QoS flow ID (QFI) in both DL and UL packets. The SDAP sublayer offers to 5GC QoS flows.

A radio resource control (RRC) layer belongs to L3. The RRC layer is only defined in the control plane. The RRC layer controls radio resources between the UE and the network. To this end, the RRC layer exchanges RRC messages between the UE and the BS. The main services and functions of the RRC layer include broadcast of system information related to AS and NAS, paging, establishment, maintenance and release of an RRC connection between the UE and the network, security functions including key management, establishment, configuration, maintenance and release of radio bearers, mobility functions, QoS management functions, UE measurement reporting and control of the reporting, NAS message transfer to/from NAS from/to UE.

In other words, the RRC layer controls logical channels, transport channels, and physical channels in relation to the configuration, reconfiguration, and release of radio bearers. A radio bearer refers to a logical path provided by L1 (PHY layer) and L2 (MAC/RLC/PDCP/SDAP sublayer) for data transmission between a UE and a network. Setting the radio bearer means defining the characteristics of the radio protocol layer and the channel for providing a specific service, and setting each specific parameter and operation method. Radio bearer may be divided into signaling RB (SRB) and data RB (DRB). The SRB is used as a path for transmitting RRC messages in the control plane, and the DRB is used as a path for transmitting user data in the user plane.

An RRC state indicates whether an RRC layer of the UE is logically connected to an RRC layer of the E-UTRAN. In LTE/LTE-A, when the RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in the RRC connected state (RRC_CONNECTED). Otherwise, the UE is in the RRC idle state (RRC_IDLE). In NR, the RRC inactive state (RRC_INACTIVE) is additionally introduced. RRC_INACTIVE may be used for various purposes. For example, the massive machine type communications (MMTC) UEs can be efficiently managed in RRC_INACTIVE. When a specific condition is satisfied, transition is made from one of the above three states to the other.

A predetermined operation may be performed according to the RRC state. In RRC_IDLE, public land mobile network (PLMN) selection, broadcast of system information (SI), cell re-selection mobility, core network (CN) paging and discontinuous reception (DRX) configured by NAS may be performed. The UE shall have been allocated an identifier (ID) which uniquely identifies the UE in a tracking area. No RRC context stored in the BS.

In RRC_CONNECTED, the UE has an RRC connection with the network (i.e. E-UTRAN/NG-RAN). Network-CN connection (both C/U-planes) is also established for UE. The UE AS context is stored in the network and the UE. The RAN knows the cell which the UE belongs to. The network can transmit and/or receive data to/from UE. Network controlled mobility including measurement is also performed.

Most of operations performed in RRC_IDLE may be performed in RRC_INACTIVE. But, instead of CN paging in RRC_IDLE, RAN paging is performed in RRC_INACTIVE. In other words, in RRC_IDLE, paging for mobile terminated (MT) data is initiated by core network and paging area is managed by core network. In RRC_INACTIVE, paging is initiated by NG-RAN, and RAN-based notification area (RNA) is managed by NG-RAN. Further, instead of DRX for CN paging configured by NAS in RRC_IDLE, DRX for RAN paging is configured by NG-RAN in RRC_INACTIVE. Meanwhile, in RRC_INACTIVE, 5GC-NG-RAN connection (both C/U-planes) is established for UE, and the UE AS context is stored in NG-RAN and the UE. NG-RAN knows the RNA which the UE belongs to.

NAS layer is located at the top of the RRC layer. The NAS control protocol performs the functions, such as authentication, mobility management, security control.

The physical channels may be modulated according to OFDM processing and utilizes time and frequency as radio resources. The physical channels consist of a plurality of orthogonal frequency division multiplexing (OFDM) symbols in time domain and a plurality of subcarriers in frequency domain. One subframe consists of a plurality of OFDM symbols in the time domain. A resource block is a resource allocation unit, and consists of a plurality of OFDM symbols and a plurality of subcarriers. In addition, each subframe may use specific subcarriers of specific OFDM symbols (e.g. first OFDM symbol) of the corresponding subframe for a physical downlink control channel (PDCCH), i.e. L1/L2 control channel. A transmission time interval (TTI) is a basic unit of time used by a scheduler for resource allocation. The TTI may be defined in units of one or a plurality of slots, or may be defined in units of mini-slots.

The transport channels are classified according to how and with what characteristics data are transferred over the radio interface. DL transport channels include a broadcast channel (BCH) used for transmitting system information, a downlink shared channel (DL-SCH) used for transmitting user traffic or control signals, and a paging channel (PCH) used for paging a UE. UL transport channels include an uplink shared channel (UL-SCH) for transmitting user traffic or control signals and a random access channel (RACH) normally used for initial access to a cell.

Different kinds of data transfer services are offered by MAC sublayer. Each logical channel type is defined by what type of information is transferred. Logical channels are classified into two groups: control channels and traffic channels.

Control channels are used for the transfer of control plane information only. The control channels include a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH) and a dedicated control channel (DCCH). The BCCH is a DL channel for broadcasting system control information. The PCCH is DL channel that transfers paging information, system information change notifications. The CCCH is a channel for transmitting control information between UEs and network. This channel is used for UEs having no RRC connection with the network. The DCCH is a point-to-point bi-directional channel that transmits dedicated control information between a UE and the network. This channel is used by UEs having an RRC connection.

Traffic channels are used for the transfer of user plane information only. The traffic channels include a dedicated traffic channel (DTCH). The DTCH is a point-to-point channel, dedicated to one UE, for the transfer of user information. The DTCH can exist in both UL and DL.

Regarding mapping between the logical channels and transport channels, in DL, BCCH can be mapped to BCH, BCCH can be mapped to DL-SCH, PCCH can be mapped to PCH, CCCH can be mapped to DL-SCH, DCCH can be mapped to DL-SCH, and DTCH can be mapped to DL-SCH. In UL, CCCH can be mapped to UL-SCH, DCCH can be mapped to UL-SCH, and DTCH can be mapped to UL-SCH.

Hereinafter, Maintenance of Uplink Time Alignment, by a wireless device, will be described. It may be referred to as Section 5.2 of 3GPP TS 36.321 V15.2.0 (2018-07).

The MAC entity has a configurable timer timeAlignmentTimer per TAG. The timeAlignmentTimer is used to control how long the MAC entity considers the Serving Cells belonging to the associated TAG to be uplink time aligned.

The MAC entity shall:

1> when a Timing Advance Command MAC control element is received and if a NTA has been stored or maintained with the indicated TAG:

2> apply the Timing Advance Command for the indicated TAG;

2> start or restart the timeAlignmentTimer associated with the indicated TAG.

1> when a Timing Advance Command is received in a Random Access Response message for a serving cell belonging to a TAG:

2> if the Random Access Preamble was not selected by the MAC entity:

3> apply the Timing Advance Command for this TAG;

3> start or restart the timeAlignmentTimer associated with this TAG.

2> else, if the timeAlignmentTimer associated with this TAG is not running:

3> apply the Timing Advance Command for this TAG;

3> start the timeAlignmentTimer associated with this TAG;

3> when the contention resolution is considered not successful, stop timeAlignmentTimer associated with this TAG.

2> else:

3> ignore the received Timing Advance Command.

1> when the MAC entity is configured with rach-Skip or rach-SkipSCG:

2> apply timing advance value indicated by targetTA in rach-Skip or rach-SkipSCG for the pTAG;

2> start the timeAlignmentTimer associated with this TAG.

1> when a timeAlignmentTimer expires:

2> if the timeAlignmentTimer is associated with the pTAG:

3> flush all HARQ buffers for all serving cells;

3> notify RRC to release PUCCH/SPUCCH for all serving cells;

3> notify RRC to release SRS for all serving cells;

3> for NB-IoT, notify RRC to release all dedicated resources for SR;

3> clear any configured downlink assignments and uplink grants;

3> consider all running timeAlignmentTimers as expired;

2> else if the timeAlignmentTimer is associated with an sTAG, then for all Serving Cells belonging to this TAG:

3> flush all HARQ buffers;

3> notify RRC to release SRS;

3> notify RRC to release PUCCH/SPUCCH, if configured;

3> clear any configured downlink assignments and uplink grants.

When the MAC entity stops uplink transmissions for an SCell due to the fact that the maximum uplink transmission timing difference or the maximum uplink transmission timing difference the UE can handle between TAGS of any MAC entity of the UE is exceeded, the MAC entity considers the timeAlignmentTimer associated with the SCell as expired.

The MAC entity shall not perform any uplink transmission on a Serving Cell except the Random Access Preamble transmission when the timeAlignmentTimer associated with the TAG to which this Serving Cell belongs is not running. Furthermore, when the timeAlignmentTimer associated with the pTAG is not running, the MAC entity shall not perform any uplink transmission on any Serving Cell except the Random Access Preamble transmission on the SpCell.

The MAC entity shall not perform any sidelink transmission which is performed based on UL timing of the corresponding serving cell and any associated SCI transmissions when the corresponding timeAlignmentTimer is not running.

NOTE: A MAC entity stores or maintains NTA upon expiry of associated timeAlignmentTimer. The MAC entity applies a received Timing Advance Command MAC control element and starts associated timeAlignmentTimer also when the timeAlignmentTimer is not running.

Hereinafter, Semi-Persistent Scheduling, by a wireless device, will be described. It may be referred to as Section 5.10 of 3GPP TS 36.321 V15.2.0 (2018-07).

Multiple UL Semi-Persistent Scheduling configurations are supported per Serving Cell. On one Serving Cell, multiple such configurations can be active simultaneously only for the same TTI length. Multiple configurations can also be active simultaneously on different Serving Cells.

When Semi-Persistent Scheduling is enabled by RRC:

1> Semi-Persistent Scheduling C-RNTI or UL Semi-Persistent Scheduling V-RNTI;

1> Uplink Semi-Persistent Scheduling interval semiPersistSchedIntervalUL if short TTI in UL for the SpCell is not configured or semiPersistSchedIntervalUL-sTTI in UL for the SpCell if short TTI is configured and number of empty transmissions before implicit release implicitReleaseAfter, if Semi-Persistent Scheduling with Semi-Persistent Scheduling C-RNTI is enabled for the uplink;

1> Uplink Semi-Persistent Scheduling interval semiPersistSchedIntervalUL and number of empty transmissions before implicit release implicitReleaseAfter for each SPS configuration, if Semi-Persistent Scheduling with UL Semi-Persistent Scheduling V-RNTI is enabled for the uplink;

1> Whether twoIntervalsConfig is enabled or disabled for uplink, only for TDD;

1> Downlink Semi-Persistent Scheduling interval semiPersistSchedIntervalDL if short TTI in DL for the SpCell is not configured or semiPersistSchedIntervalDL-sTTI if short TTI in DL for the SpCell is configured and number of configured HARQ processes for Semi-Persistent Scheduling numberOfConfSPS-Processes, if Semi-Persistent Scheduling is enabled for the downlink;

1> sTTIStartTimeDl if short TTI in DL for the SpCell is configured and sTTIStartTimeUl if short TTI in UL for the SpCell is configured;

When Semi-Persistent Scheduling for uplink or downlink is disabled by RRC, the corresponding configured grant or configured assignment shall be discarded.

Semi-Persistent Scheduling is not supported for RN communication with the E-UTRAN in combination with an RN subframe configuration.

NOTE: When eIMTA is configured, if a configured uplink grant or a configured downlink assignment occurs on a subframe that can be reconfigured through eIMTA L1 signalling, then the UE behaviour is left unspecified.

Hereinafter, Downlink and Uplink of Semi-Persistent Scheduling, by a wireless device, will be described.

After a Semi-Persistent downlink assignment is configured, the MAC entity shall consider sequentially that the Nth assignment occurs in the TTI for which:

1> subframe SPS is used:

2> (10*SFN+subframe)=[(10*SFNstart time+subframestart time)+N*semiPersistSchedIntervalDL] modulo 10240.

1> slot or subslot SPS is used:

2> (10*SFN*sTTI_Number_Per_Subframe+subframe*sTTI_Number_Per_Subframe+sTTI_number)=[(10*SFNstart time*sTTI_Number_Per_Subframe+subframestart time*sTTI_Number_Per_Subframe+sTTIStartTimeDl)+N*semiPersistSchedIntervalDL-sTTI] modulo (10240*sTTI_Number_Per_Subframe).

Where SFNstart time, subframestart time and sTTIStartTimeDl are the SFN, subframe and sTTI_number, respectively, at the time the configured downlink assignment were (re-)initialised. The sTTI_Number_Per_Subframe is 6 when subslot TTI is configured and 2 when slot TTI is configured for short TTI operation. sTTI_number refers to the index of the short TTI, i.e., index of subslot or slot within the subframe.

For BL UEs or UEs in enhanced coverage SFNstart time and subframestart time refer to SFN and subframe of the first transmission of PDSCH where configured downlink assignment was (re-)initialized.

After a Semi-Persistent Scheduling uplink grant is configured, the MAC entity shall:

1> if twoIntervalsConfig is enabled by upper layer:

2> set the Subframe_Offset.

1> else:

2> set Subframe_Offset to 0.

1> consider sequentially that the Nth grant occurs in the TTI for which:

2> subframe SPS is used:

3> (10*SFN+subframe)=[(10*SFNstart time+subframestart time)+N*semiPersistSchedIntervalUL+Subframe_Offset*(N modulo 2)] modulo 10240.

2> slot or subslot SPS is used:

3> (10*SFN*sTTI_Number_Per_Subframe+subframe*sTTI_Number_Per_Subframe+sTTI_number)=[(10*SFNstart time*sTTI_Number_Per_Subframe+subframestart time*sTTI_Number_Per_Subframe+sTTlStartTimeUl)+N*semiPersistSchedIntervalUL-sTTI+Subframe_Offset*(N modulo 2)*sTTI_Number_Per_Subframe] modulo (10240*sTTI_Number_Per_Subframe).

Where SFNstart time, subframestart time and sTTlStartTimeUl are the SFN, subframe and sTTI_number, respectively, at the time the configured uplink grant were (re-)initialised. The sTTI_Number_Per_Subframe is 6 when subslot TTI is configured and 2 when slot TTI is configured for short TTI operation. sTTI_number refers to the index of the short TTI, i.e., index of subslot or slot within the subframe.

Except for NB-IoT, for TDD, the MAC entity is configured with semiPersistSchedIntervalUL shorter than 10 subframes, the Nth grant shall be ignored if it occurs in a downlink subframe or a special subframe.

Except for NB-IoT, if the MAC entity is not configured with skipUplinkTxSPS, the MAC entity shall clear the configured uplink grant immediately after implicitReleaseAfter number of consecutive new MAC PDUs each containing zero MAC SDUs have been provided by the Multiplexing and Assembly entity, on the Semi-Persistent Scheduling resource.

If SPS confirmation has been triggered and not cancelled:

1> if the MAC entity has UL resources allocated for new transmission for this TTI:

2> instruct the Multiplexing and Assembly procedure to generate an SPS confirmation MAC Control Element;

2> cancel the triggered SPS confirmation.

The MAC entity shall clear the configured uplink grant immediately after first transmission of SPS confirmation MAC Control Element triggered by the SPS release.

NOTE: Retransmissions for Semi-Persistent Scheduling can continue after clearing the configured uplink grant.

For NB-IoT UEs, BL UEs or UEs in enhanced coverage SFNstart time and subframestart time refer to SFN and subframe of the first transmission of PUSCH where configured uplink grant was (re-)initialized.

In the event of a resource conflict between multiple UL SPS configurations configured with Uplink Semi-Persistent Scheduling V-RNTI, the UE behavior is undefined.

For NB-IoT UEs, a configured uplink grant shall be used only for BSR transmission and uplink skip mechanism is implicitly supported.

Hereinafter, uplink transmission without dynamic scheduling, by a wireless device, will be described. It may be referred to as Section 5.8.2 of 3GPP TS 38.321 V15.3.0 (2018-09).

There are two types of transmission without dynamic grant:

-   -   configured grant Type 1 where an uplink grant is provided by         RRC, and stored as configured uplink grant;     -   configured grant Type 2 where an uplink grant is provided by         PDCCH, and stored or cleared as configured uplink grant based on         L1 signalling indicating configured uplink grant activation or         deactivation.

Type 1 and Type 2 are configured by RRC per Serving Cell and per BWP. Multiple configurations can be active simultaneously only on different Serving Cells. For Type 2, activation and deactivation are independent among the Serving Cells. For the same Serving Cell, the MAC entity is configured with either Type 1 or Type 2.

RRC configures the following parameters when the configured grant Type 1 is configured:

-   -   cs-RNTI: CS-RNTI for retransmission;     -   periodicity: periodicity of the configured grant Type 1;     -   timeDomainOffset: Offset of a resource with respect to SFN=0 in         time domain;     -   timeDomainAllocation: Allocation of configured uplink grant in         time domain which contains startSymbolAndLength (i.e. SLIV);     -   nrofHARQ-Processes: the number of HARQ processes for configured         grant.

RRC configures the following parameters when the configured grant Type 2 is configured:

-   -   cs-RNTI: CS-RNTI for activation, deactivation, and         retransmission;     -   periodicity: periodicity of the configured grant Type 2;     -   nrofHARQ-Processes: the number of HARQ processes for configured         grant.

Upon configuration of a configured grant Type 1 for a Serving Cell by upper layers, the MAC entity shall:

1> store the uplink grant provided by upper layers as a configured uplink grant for the indicated Serving Cell;

1> initialise or re-initialise the configured uplink grant to start in the symbol according to timeDomainOffset and S (derived from SLIV), and to reoccur with periodicity.

When a configured uplink grant is released by upper layers, all the corresponding configurations shall be released and all corresponding uplink grants shall be cleared.

The MAC entity shall:

1> if the configured uplink grant confirmation has been triggered and not cancelled; and

1> if the MAC entity has UL resources allocated for new transmission:

2> instruct the Multiplexing and Assembly procedure to generate an Configured Grant Confirmation MAC CE;

2> cancel the triggered configured uplink grant confirmation.

For a configured grant Type 2, the MAC entity shall clear the configured uplink grant immediately after first transmission of Configured Grant Confirmation MAC CE triggered by the configured uplink grant deactivation.

Retransmissions except for repetition of configured uplink grants use uplink grants addressed to CS-RNTI.

The RRC inactive state is described in detail. The following description of the RRC inactive state will be described by taking NR as an example, but it can be applied to LTE-A without loss of generality. For example, in the following description, NG-RAN node/gNB may be replaced with eNB and/or more generally BS, and AMF may be replaced with MME.

The RRC inactive state applies to NG-RAN node. The AMF, based on network configuration, may provide RRC inactive assistance information to the NG-RAN node, to assist the NG-RAN's decision whether the UE can be sent to RRC inactive state.

The RRC inactive assistance information includes at least one of the followings.

-   -   UE specific DRX values     -   The registration area provided to the UE     -   Periodic registration update timer     -   If the AMF has enabled mobile initiated connection only (MICO)         mode for the UE, an indication that the UE is in MICO mode.     -   Information from the UE permanent identifier that allows the         NG-RAN node to calculate the UE's RAN paging occasions.

The RRC inactive assistance information mentioned above is provided by the AMF during N2 activation with the (new) serving NG-RAN node (i.e. during registration, service request, handover) to assist the NG-RAN node's decision whether the UE can be sent to RRC inactive state. RRC inactive state is part of RRC state machine, and it is up to the NG-RAN node to determine the conditions to enter RRC inactive state. If any of the parameters included in the RRC inactive assistance information changes as the result of NAS procedure, the AMF shall update the RRC inactive assistance information to the NG-RAN node.

When the UE is in connection management connected state (CM-CONNECTED), if the AMF has provided RRC inactive assistance information, the NG-RAN node may decide to move a UE to CM-CONNECTED with RRC inactive state.

The state of the N2 and N3 reference points are not changed by the UE entering CM-CONNECTED with RRC inactive state. A UE in RRC inactive state is aware of the RAN notification area.

The 5GC network is not aware of the UE transitions between CM-CONNECTED with RRC_CONNECTED and CM-CONNECTED with RRC inactive state, unless the 5GC network is notified via N2 notification procedure.

At transition into CM-CONNECTED with RRC inactive state, the NG-RAN node configures the UE with a periodic RAN notification area update timer taking into account the value of the periodic registration update timer value indicated in the RRC inactive assistance information, and uses a guard timer with a value longer than the RAN notification area update timer value provided to the UE.

If the periodic RAN notification area update guard timer expires in NG-RAN node, the NG-RAN node shall initiate access network (AN) release procedure.

When the UE is in CM-CONNECTED with RRC inactive state, the UE performs PLMN selection procedures for connection management idle state (CM-IDLE).

When the UE is CM-CONNECTED with RRC inactive state, the UE may resume the RRC connection due to at least one of the followings.

-   -   UL data pending     -   Mobile originated (MO) NAS signaling procedure     -   As a response to RAN paging     -   Notifying the network that it has left the RAN notification area     -   Upon periodic RAN update timer expiration.

If the UE resumes the connection in a different NG-RAN node within the same PLMN, the UE AS context is retrieved from the old NG-RAN node and a procedure is triggered towards the CN.

If the RAN paging procedure is not successful in establishing contact with the UE, the procedure shall be handled by the network as follows.

-   -   If NG-RAN node has at least one pending NAS PDU for         transmission, the NG-RAN node shall initiate the AN release         procedure to move the UE CM state in the AMF to CM-IDLE and         indicate to the AMF the NAS non-delivery.     -   If NG-RAN node has only pending user plane data for         transmission, the NG-RAN node may keep the N2 connection active         or initiate the AN release procedure based on local         configuration in NG-RAN node.

The user plane data which triggers the RAN paging can be lost, e.g. in the case of RAN paging failure.

If a UE in CM-CONNECTED with RRC inactive state performs cell selection to GERAN/UTRAN/E-UTRAN, it shall follow idle mode procedures of the selected RAT.

In addition, a UE in CM-CONNECTED state with RRC inactive state shall enter CM-IDLE and initiates the NAS signaling recovery in at least one of the following cases.

-   -   If RRC resume procedure fails;     -   If the UE receives core network paging;     -   If the periodic RAN notification area update timer expires and         the UE cannot successfully resume the RRC connection;     -   In any other failure scenario that cannot be resolved in RRC         inactive state and requires the UE to move to CM-IDLE.

When the UE is in CM-CONNECTED with RRC inactive state, if NG-RAN node has received location reporting control message from AMF with the reporting type indicating single stand-alone report, the NG-RAN node shall perform RAN paging before reporting the location to AMF.

When the UE is in CM-CONNECTED with RRC inactive state, if NG-RAN node has received location reporting control message from AMF with the reporting type indicating continuously reporting whenever the UE changes cell, the NG-RAN node shall send a location report message to AMF including UE's last known location with time stamp.

When the UE is CM-CONNECTED with RRC inactive state, if the AMF receives Nudm_UEContextManagement_DeregistrationNotification from user data management (UDM), the AMF shall initiate AN release procedure.

When UE is in CM-CONNECTED with RRC inactive state, if NG-RAN node has received location reporting control message from AMF with the reporting type of the area of interest based reporting, the NG-RAN node shall send a location report message to AMF including UE presence in the area of interest (i.e. IN, OUT, or UNKNOWN) and the UE's last known location with time stamp.

FIG. 7 shows an example of a connection resume procedure to which the technical features of the present disclosure can be applied. The connection resume procedure is used by the UE to perform RRC inactive to RRC connected state transition.

In step S700, while the UE is in RRC_INACTIVE, the UE transmits an RRC message to the NG-RAN node to initiate the transition from RRC_INACTIVE to RRC_CONNECTED. The UE provides its resume ID needed by the NG-RAN node to access the UE's stored context. The RRC message may be RRCConnectionResumeRequest message which will be described in detail below.

In step S702, the NG-RAN node may conditionally perform UE context retrieval. The UE context retrieval is performed when the UE context associated with the UE attempting to resume its connection is not locally available at the accessed NG-RAN node.

In step S704, the NG-RAN node may conditionally perform N2 path switch procedure towards the serving AMF. If the target NG-RAN node is different from the old NG-RAN node, the serving NG-RAN node initiates N2 path switch procedure and including Xn data forwarding. The NG-RAN node sends UE notification message to report that the UE is in RRC_CONNECTED if the AMF requested N2 notification to the NG-RAN node.

In step S706, the NG-RAN node transmits an RRC message to the UE to confirm to the UE that the UE has entered RRC_CONNECTED. The RRC message includes resume ID of the UE.

The RRC connection release is described in detail. It may be referred to as Section 5.3 of 3GPP TS 38.331 V15.3.0 (2018-09).

The purpose of the RRC connection release procedure is:

1> to release the RRC connection, which includes the release of the established radio bearers as well as all radio resources; or

1> to suspend the RRC connection, which includes the suspension of the established radio bearers.

The network initiates the RRC connection release procedure to transit a UE in RRC_CONNECTED to RRC_IDLE; or to transit a UE in RRC_CONNECTED to RRC_INACTIVE; or to transit a UE in RRC_INACTIVE back to RRC_INACTIVE when the UE tries to resume; or to transit a UE in RRC_INACTIVE to RRC_IDLE when the UE tries to resume. The procedure can also be used to release and redirect a UE to another frequency.

UE actions upon going to RRC_IDLE is described in detail.

UE shall:

1> reset MAC;

1> stop all timers that are running except T320 and T325;

1> discard any stored AS context, fullI-RNTI, shortI-RNTI-Value, ran-PagingCycle and ran-NotificationAreaInfo;

1> discard the AS security context including the KRRCenc key, the KRRCint, the KUPint key and the KUPenc key, if stored;

1> release all radio resources, including release of the RLC entity, the MAC configuration and the associated PDCP entity and SDAP for all established RBs;

1> indicate the release of the RRC connection to upper layers together with the release cause;

1> enter RRC_IDLE and perform procedures, except if going to RRC_IDLE was triggered by reception of the MobilityFromNRCommand message or by selecting an inter-RAT cell while T311 was running.

A wireless device may transmit data in RRC_IDLE state or RRC_INACTIVE state with a network. For example, a wireless device may be configured with configured grant to transmit user data in RRC_IDLE state or RRC_INACTIVE state. However, when the configured grant is not valid and/or uplink timing is not aligned with the network, a wireless device could not use the configured grant to transmit user data in RRC_IDLE state or RRC_INACTIVE state. Therefore, a method for entering a connected state with the network for continuing transmission in wireless communication system is required.

Hereinafter, a method and a wireless device for entering a connected state with the network to continuing data transmission, according to some embodiments of the present disclosure, will be described with reference to following drawings.

The following drawings are created to explain specific embodiments of the present disclosure. The names of the specific devices or the names of the specific signals/messages/fields shown in the drawings are provided by way of example, and thus the technical features of the present disclosure are not limited to the specific names used in the following drawings.

FIG. 8 shows an example of a method for entering a connected state with a network for continuing transmission, according to some embodiments of the present disclosure. More specifically, FIG. 8 shows an example of an embodiment of the present disclosure on perspective of a wireless device.

In step 801, a wireless device may start or restart a Time Alignment Timer (TAT). A wireless device may have a configurable time alignment timer (TAT) per timing advance group (TAG), wherein a TAG may include one or more serving cells with the same uplink timing advancing (TA) and downlink timing reference cell.

For example, a wireless device may start or restart a TAT when a Timing Advance Command (TAC) MAC control element (CE) is received. When a TAC indicates a specific TAG, a wireless device may start or restart a TAT associated with the specific TAG. For other example, a wireless device may start or restart a TAT when a TAC is received in a Random Access Response message for a serving cell belonging to a TAG. For another example, when a MAC entity of a wireless device is configured with rach-skip or rach-skipSCG for primary timing advance group (pTAG), such as PCell, the wireless device may start a TAT associated with the TAG.

According to some embodiments of the present disclosure, a wireless device may start or restart a TAT while in RRC_CONNECTED. The wireless device may continue running TAT after leaving RRC_CONNECTED.

In step 802, a wireless device may receive configuration of a configured grant upon leaving RRC_CONNECTED. A wireless device may receive configuration of a configured grant applicable to a validity area with a validity timer upon leaving RRC_CONNECTED. The configured grant may be a resource of a Semi-Persistent Scheduling (SPS) configuration. The validity area consists of one or more cells.

According to some embodiments of the present disclosure, the configuration of the configured grant may include a maximum amount of data (or maximum data rate) supported by the configured grant. The configuration of the configured grant may include a wireless device Identity (for example, a UE Identity), such as a SPS-I-RNTI, which is used by the wireless device when the wireless device performs uplink transmission with the configured grant or downlink reception while in RRC_IDLE or RRC_INACTIVE.

In step 803, a wireless device may select a cell belonging to the validity area and camp on the selected cell. A wireless device may select a cell and camp on the selected cell, being in RRC_IDLE or RRC_INACTIVE.

In step 804, a wireless device may initiate uplink transmission of a RRC Request message to enter RRC_CONNECTED. A wireless device may perform random access procedure to send the RRC Request message.

A wireless device may initiate uplink transmission of the RRC Request message when the Timer Alignment Timer (TAT) is expired. A wireless device may initiate uplink transmission of the RRC Request message when the Timer Alignment Timer (TAT) is expired and data becomes available.

A wireless device may initiate uplink transmission of the RRC Request message when the validity timer associated with the configured grant expires. A wireless device may initiate uplink transmission of the RRC Request message when the validity timer associated with the configured grant expires.

A wireless device may initiate uplink transmission of the RRC Request message when the wireless device leaves the validity area associated with the configured grant. A wireless device may initiate uplink transmission of the RRC Request message when the wireless device leaves the validity area associated with the configured grant and data becomes available.

A wireless device may initiate uplink transmission of the RRC Request message when data becomes available for a logical channel not mapped to SPS configuration.

A wireless device may initiate uplink transmission of the RRC Request message when data becomes available and the amount of data available for transmission is beyond the maximum amount of data. A wireless device may initiate uplink transmission of the RRC Request message when data becomes available and the amount of data available for transmission is beyond the maximum data rate.

FIG. 9 shows a flow chart of an example of a method for entering a connected state with a network for continuing transmission, according to some embodiments of the present disclosure. More specifically, FIG. 9 shows an example of an embodiment of the present disclosure on perspective of a network system. The description of the same parts as those described above will be simplified or omitted.

In step 901, a wireless device may receive configuration for RRC setup from a network (for example, an eNB or a gNB).

In step 902, a wireless device may enter RRC_CONNECTED and EMM_CONNECTED at a serving cell.

In step 903, a wireless device may receive configuration for Security Mode Activation from a network. The wireless device may perform Security Mode Activation to activate AS security.

In step 904, a wireless device may receive RRC Connection Reconfiguration from the network to configure SPS configuration with SPS-I-RNTI. The SPS-I-RNTI may be used for data transmission in RRC_IDLE. The wireless device may receive SPS configuration via system information regardless of RRC state.

According to some embodiments of the present disclosure, a wireless device may start or restart TAT while in RRC_CONNECTED. A wireless device may continue running TAT after leaving RRC_CONNECTED.

According to some embodiments of the present disclosure, a SPS configuration may include uplink and/or downlink SPS resources as uplink and/or downlink configured grants, PRB or narrowband index. A SPS configuration may include a validity area, a validity timer, valid logical channels, maximum amount of data, or maximum data rate supported by the configured grant. A SPS configuration may include a wireless device Identity (for example, a UE Identity) such as a SPS-I-RNTI, which is used by the wireless device when the wireless device performs uplink transmission with the configured grant. The SPS configured grant may be valid in the validity area consisting of one or more cells including the serving cell.

The SPS configuration or the SPS configured grant may be valid in the configured PRB or narrowband while a wireless device is in RRC_IDLE or RRC_INACTEVE. RRC Release, Paging, MAC Control Element or PDCCH received in RRC_IDLE or RRC_INACTIVE could indicate SPS activation with a PRB index or a narrowband index for a particular SPS configured grant. Upon receiving such SPS activation with a PRB index or a narrowband index, a wireless device in RRC_IDLE or RRC_INACTIVE may consider the SPS configured grant or the SPS configuration as activated on the PRB or the narrowband indicated by the index.

The SPS configured grant may be valid while a validity timer is running. The validity timer could be a time Alignment Timer (TAT) or another timer. The validity timer may be configured for each configured grant. A wireless device may start or restart the validity timer (e.g. TAT) when the SPS configured grant is received. A wireless device may start or restart the validity timer when a wireless device leaves RRC_CONNECTED. A wireless device may start or restart the validity timer when Timing Advance Command is received, e.g. via MAC Control Element, Random Access Response, RRC Release message, or Paging message in RRC_IDLE or RRC_INACTIVE after leaving RRC_CONNECTED. The network may periodically send Timing Advance Command to the wireless device in RRC_IDLE or RRC_INACTIVE, e.g. by paging message in Paging Occasion of the wireless device or MAC Control Element via DL SPS configured grant.

According to some embodiments of the present disclosure, the SPS configured grant may be valid only for configured valid logical channels. When a wireless device transmits data from the valid logical channel, the wireless device could use the SPS configured grant to transmit data.

In step 905, a wireless device may receive a RRC Release message from a network. The RRC Release message may include Suspend indication. The RRC Release message may include command to pre-allocated resource, such as configured grant or SPS.

In step 906, a wireless device may leave RRC_CONNECTED state. When a wireless device receives RRC Release message or RRC Release Indication (e.g. via PDCCH or MAC Control Element), the wireless device may leave RRC_CONNETED. The wireless device may enter to RRC_IDLE. When a wireless device receives a RRC Release message with a suspend indication, the wireless device may leave RRC_CONNETED. The wireless device may enter to RRC_INACTIVE. In RRC_IDLE or RRC_INACTIVE, a wireless device may transmit user data via the configured grant.

In step 907, a wireless device may have data which becomes available for transmitting to a network. A data may become available for uplink transmission.

In step 908, a wireless device may transmit a MAC PDU to a network. The wireless device may transmit a MAC PDU to a Core Network through an eNB or a gNB.

If RRC Release message (or a RRC Release message with a suspend indication) indicates uplink SPS activation for a particular SPS configured grant and if data becomes available for uplink transmission in RRC_IDLE or RRC_ACTIVE, a wireless device may construct a MAC PDU including SPS Confirmation MAC Control Element with user data. The SPS Confirmation MAC CE may indicate that which SPS configured grant(s) is activated or deactivated.

According to some embodiments of the present disclosure, a wireless device may periodically transmit SPS Confirmation MAC CE to inform the network that which SPS configured grant(s) is currently activated or deactivated.

According to some embodiments of the present disclosure, In RRC_IDLE state or RRC_INACTIVE state, a wireless device may perform cell reselection. If a wireless device performs cell reselection and camps on the selected cell belonging to the validity area, a wireless device may send SPS confirmation to a network to inform the network that which SPS configured grant(s) is currently activated or deactivated.

A wireless device in in RRC_IDLE or RRC_INACTIVE may perform uplink transmissions by using the SPS configured grant. SPS configured grant could be either contention based or contention free.

A wireless device in RRC_IDLE or RRC_INACTIVE should transmit data with an ID of the wireless device, such as SPS-I-RNTI or S-TMSI, in contention based SPS configured grant. A wireless device in RRC_IDLE or RRC_INACITVE may include an ID of the wireless device in a RRC message or a MAC CE to be transmitted from uplink.

According to some embodiments of the present disclosure, before transmitting a MAC PDU by using contention based configured grant, a wireless device in RRC_IDLE or RRC_INACTIVE may perform Access Barring Check to determine whether or not to perform transmission of the MAC PDU via the SPS configured grant based on barring information received from system information. If access attempt is allowed as the result of Access Barring Check, the wireless device may perform transmission of the MAC PDU.

The network may indicate to a wireless device whether the SPS configured grant or the SPS configuration requires Access Barring Check. Thus, if indicated, MAC of the wireless device may request RRC of the wireless device to perform Access Barring Check before transmission of the MAC PDU via the SPS configured grant. Then, RRC of the wireless device may inform MAC of the wireless device about the result of the Access Barring Check. If access attempt is allowed as the result of Access Barring Check, MAC of the wireless device may perform transmission of the MAC PDU.

According to some embodiments of the present disclosure, a wireless device in RRC_IDLE or RRC_INACTIVE should transmit a MAC PDU with ID of the wireless device, such as SPS-I-RNTI or S-TMSI, in contention based SPS configured grant. MAC entity of the wireless device may consider transmission of the MAC PDU as successful after contention resolution message as well as positive HARQ feedback is received in downlink.

According to some embodiments of the present disclosure, a wireless device in RRC_IDLE or RRC_INACTIVE could transmit data without ID of the wireless device in contention free SPS configured grant. A wireless device may not need to perform Access Barring Check before transmitting MAC PDU by using contention free SPS configured grant. In this case, MAC entity of the wireless device may consider transmission of the MAC PDU as successful after positive HARQ feedback is received in downlink without contention resolution message.

According to some embodiment of the present disclosure, when a wireless device enters RRC_IDLE (or RRC_INACTIVE) by receiving a RRC Release message (or a RRC Release message with a suspend indication), the RRC Release message (or the RRC Release message with a suspend indication) may indicate downlink SPS activation for a particular SPS configured grant. A wireless device may activate the downlink SPS configured grant. When data becomes available for downlink transmission in RRC_IDLE (or RRC_INACTIVE), the network may send user data by using the DL SPS configured grant. The network may indicates to the wireless device that the DL SPS is deactivated by sending Paging, MAC Control Element or PDCCH to the wireless device in RRC_IDLE (or RRC_INACTIVE). Then, the wireless device may transmit DL data via the SPS configured grant.

According to some embodiment of the present disclosure, when a wireless device enters RRC_IDLE (or RRC_INACTIVE) by receiving a RRC Release message (or a RRC Release message with a suspend indication), the RRC Release message (or the RRC Release message with a suspend indication) may indicate downlink SPS deactivation for a particular SPS configured grant. Otherwise, the network may indicate to the wireless device that the DL SPS is deactivated by sending Paging, MAC Control Element or PDCCH to the wireless device in RRC_IDLE (or RRC_INACTIVE). In this case, the network may indicate to the wireless device that the DL SPS is activated by sending Paging, MAC Control Element or PDCCH to the wireless device in RRC_IDLE (or RRC_INACTIVE). Then, the wireless device may transmit DL data via the SPS configured grant.

In step 909, a validity timer (e.g. a TAT) of a wireless device may be expired or the wireless device may leave the validity area.

In step 910, data in a wireless device becomes available for uplink transmission.

When the validity timer (e.g. a TAT) has been expired and/or when the data becomes available, a wireless device may initiate Random Access procedure to perform RRC Connection Establishment procedure.

When the wireless device leaves the validity area and/or when the data becomes available, a wireless device may initiate Random Access procedure to perform RRC Connection Establishment procedure.

According to some embodiments of the present disclosure, when data becomes available for a logical channel which is not mapped to the SPS configuration or the SPS configured grant, a wireless device may initiate Random Access procedure to perform RRC Connection Establishment procedure.

According to some embodiments of the present disclosure, when data becomes available and the amount of data available for transmission is beyond the maximum amount of data (or the maximum data rate), a wireless device may initiate Random Access procedure to perform RRC Connection Establishment procedure.

In step 911, a wireless device may transmit RACH preamble with a RAPID. A wireless device may deactivates the corresponding SPS configured grant or suspend the SPS configuration or release the SPS configuration. The RAPID may be associated with the SPS configuration or the SPS configured grant.

In step 912, a wireless device may receive a Random Access Response (RAR) from a network. The network sends Random Access Response (RAR) message, in response to the RACH preamble, to the wireless device.

According to some embodiments of the present disclosure, the RAR message may include RAPID, Time Advance command, and SPS-I-RNTI. The RAR message may indicate that which type of message should be sent by a wireless device (e.g. EarlyDataRequest, RRCConnectionRequest, or RRCResumeRequest). The RAR message may indicate that which procedure should be triggered by the wireless device (e.g. EDT, RRC Connection Establishment or RRC Resume procedure).

In step 913, a wireless device may transmit RRCConnectionRequest message to a network. The wireless device may transmit RRCConnectionRequest message, based on the RAR message.

According to some embodiments of the present disclosure, a wireless device may transmit RRCConnectionRequest message with user data to a network, for example an eNB or a gNB.

In step 914, an eNB or a gNB may transmit the user data received from the wireless device to a core network.

In step 915 a wireless device may receive RRCSetup message from a network. The RRCSetup message may include SPS reconfiguration and new SPS-I-RNTI

According to some embodiment of the present disclosure, a wireless device may receive SPS reconfiguration and new SPS-I-RNTI, upon receiving RRCSetup message. When a wireless device enters RRC_CONNECTED after receiving RRCSetup, the wireless device may transmit user data possibly with RRC Connection Setup Complete.

According to an embodiment of the present disclosure described above, when data becomes available and if the configured grant cannot be used and/or uplink timing is not aligned with the network, the UE can transmit RRC request message to the network in order to enter RRC_CONNECTED from RRC_IDLE or RRC_INACTIVE. After entering RRC_CONNECTED, the UE can align UL timing with the network and/or SPS configuration can be reconfigured. Therefore, the UE can continue data transmission.

FIG. 10 shows a method for entering a connected state with a network for continuing data transmission, according to some embodiments of the present disclosure. The description of the same parts as those described above will be simplified or omitted.

In step 1001, a wireless device may start or restart a Time Alignment Timer (TAT). For example, a wireless device may start or restart a TAT upon receiving a Timing Advance Command (TAC) MAC control element (CE). For other example, a wireless device may start or restart a TAT upon receiving a TAC in a Random Access Response message for a serving cell belonging to a TAG.

According to some embodiments of the present disclosure, a wireless device may start or restart a TAT in a connected state (e.g. RRC CONNECTED state) with a network. For example, a wireless device may restart the TAT, and continue running the TAT after leaving the connected state. A wireless device may not restart the TAT upon leaving the connected state.

According to some embodiments of the present disclosure, a wireless device may restart a TAT when the wireless device enters to RRC INACTIVE state or RRC IDLE state from RRC CONNECTED state.

In step 1002, a wireless device may leave a connected state with a network. A wireless device may leave a RRC_CONNECTED state with a network. A wireless device may release RRC_CONNECTED state and enter RRC_IDLE state. A wireless device may suspend (or release with suspend) RRC_CONNECTED state and enter RRC_INACTIVE state.

In step 1003, a wireless device may perform transmission with a configured grant. A wireless device may perform the transmission, while in leaving the connected state. A wireless device may perform the transmission in RRC_IDLE or RRC_INACTIVE state.

A wireless device, while in leaving a connected state with a network, may perform transmission with a configured grant, wherein configuration of the configured grant may be received from a network. For example, a wireless device may use a resource of pre-allocated resource (for example, configured grant or a SPS configuration) for transmission. According to some embodiments of the present disclosure, a configured grant for data transmission while in leaving a connected state may be a resource of a SPS configuration.

According to some embodiments of the present disclosure, a wireless device may receive configuration of the configured grant before leaving the connected state. A wireless device may receive configuration of the configured grant upon leaving the connected state. A wireless device may receive configuration of the configured grant from a network in a connected state with the network. For example, a wireless device may receive configuration of the configured grant in RRC_CONNECTED state.

According to some embodiments of the present disclosure, a wireless device may receive configuration of the configured grant while in leaving a connected state with a network. For example, a wireless device may receive a configured grant (or a SPS configuration) in RRC_IDLE state or RRC_INACTIVE state. For other example, a wireless device may receive SPS configuration via system information regardless of RRC state.

According to some embodiments of the present disclosure, a configuration of a configured grant may include a maximum amount of data supported by the configured grant. A configuration of a configured grant may include an identity of the wireless device which is used by the wireless device when the wireless device performs uplink transmission with the configured grant or downlink reception, while in leaving the connected state.

According to some embodiments of the present disclosure, a wireless device, while in leaving a connected state with a network, may select or reselect a cell (for example, a suitable and accessible cell) and camp on the cell. The wireless device may receive a configured grant from the selected cell.

In step 1004, a wireless device may perform a random access (RA) to the network, after the TAT is expired. A wireless device may perform a RA to the network, when the TAT is expired. A wireless device may perform a RA to the network, when the TAT is expired and data (for example, data for transmitting from the wireless device to the network) becomes available.

A wireless device may release or deactivate a configured grant upon the TAT is expired, while in leaving the connected state. When a TAT is expired, a wireless device may deactivate to transmit data using the configured grant. While deactivating the configured grant, when data from the wireless device becomes available, the wireless device may try to enter a connected state with a network by performing a RA.

A wireless device may initiate uplink transmission of a RRC Request message to enter the connected state with the network. For example, a RA procedure may include initiating uplink transmission of a RRC Request message.

A wireless device may enter a connected state with a network by performing a RA to the network, after the TAT is expired. A wireless device may receive reconfiguration of a configured grant. A wireless device may align a time advance and restart or start a TAT.

According to some embodiments of the present disclosure, a wireless device may receive a RRCSetup message. A wireless device may enter a connected state with a network. A wireless device may receive a configuration for resource of transmission. A wireless device may receive SPS reconfiguration and new SPS-I-RNTI. A wireless device may transmit user data in the connected state. A wireless device may perform transmission with the network in the connected state.

According to some embodiments of the present disclosure, a wireless device may be an autonomous driving apparatus in communication with at least one of a mobile terminal, a network, and/or autonomous vehicles other than the wireless device.

According to some embodiments of the present disclosure, a wireless device may perform a RA to a network in order to enter a connected state (e.g. RRC_CONNECTED) with the network, when a TAT is expired. After entering the connected state, the wireless device may align UL timing with the network and/or reconfigure the configured grant for data transmission. Therefore, the wireless device could continue data transmission.

According to some embodiments of the present disclosure, a wireless device may keep running a TAT when the wireless device leaves a connected state with a network. A wireless device may use the TAT for checking validity of a configured grant. When the TAT is expired the wireless device may deactivate the configured grant.

FIG. 11 shows an apparatus for entering a connected state with a network after a TAT is expired, according to some embodiments of the present disclosure. The description of the same parts as those described above will be simplified or omitted. An apparatus may be referred as a wireless device, such as a user equipment (UE), an Integrated Access and Backhaul (IAB), or etc.

A wireless device includes a processor 1110, a power management module 1111, a battery 1112, a display 1113, a keypad 1114, a subscriber identification module (SIM) card 1115, a memory 1120, a transceiver 1130, one or more antennas 1131, a speaker 1140, and a microphone 1141.

The processor 1110 may be configured to implement proposed functions, procedures and/or methods described in this description. Layers of the radio interface protocol may be implemented in the processor 1110. The processor 1110 may include application-specific integrated circuit (ASIC), other chipset, logic circuit and/or data processing device. The processor 1110 may be an application processor (AP). The processor 1110 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), a modem (modulator and demodulator). An example of the processor 1110 may be found in SNAPDRAGON™ series of processors made by Qualcomm®, EXYNOS™ series of processors made by Samsung®, A series of processors made by Apple®, HELIO™ series of processors made by MediaTek®, ATOM™ series of processors made by Intel® or a corresponding next generation processor.

The power management module 1111 manages power for the processor 1110 and/or the transceiver 1130. The battery 1112 supplies power to the power management module 1111. The display 1113 outputs results processed by the processor 1110. The keypad 1114 receives inputs to be used by the processor 1110. The keypad 1114 may be shown on the display 1113. The SIM card 1115 is an integrated circuit that is intended to securely store the international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers). It is also possible to store contact information on many SIM cards.

The memory 1120 is operatively coupled with the processor 1110 and stores a variety of information to operate the processor 1110. The memory 1120 may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and/or other storage device. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The modules can be stored in the memory 1120 and executed by the processor 1110. The memory 1120 can be implemented within the processor 1110 or external to the processor 1110 in which case those can be communicatively coupled to the processor 1110 via various means as is known in the art.

The transceiver 1130 is operatively coupled with the processor 1110, and transmits and/or receives a radio signal. The transceiver 1130 includes a transmitter and a receiver. The transceiver 1130 may include baseband circuitry to process radio frequency signals. The transceiver 1130 controls the one or more antennas 1131 to transmit and/or receive a radio signal.

The speaker 1140 outputs sound-related results processed by the processor 1110. The microphone 1141 receives sound-related inputs to be used by the processor 1110.

According to some embodiments of the present disclosure, the processor 1110 may be configured to be coupled operably with the memory 1120 and the transceiver 1130. The processor 1110 may be configured to start a Time Alignment Timer (TAT). The processor 1110 may be configured to leave a connected state with a network. The processor 1110 may be configured to perform transmission with a configured grant, wherein the configured grant is received from the network, while in leaving the connected state. The processor 1110 may be configured to perform a random access (RA) to the network after the TAT is expired, while in leaving the connected state.

According to some embodiments of the present disclosure shown in FIG. 11, a wireless device may perform a RA to a network in order to enter a connected state (e.g. RRC_CONNECTED) with the network, when a TAT is expired. After entering the connected state, the wireless device may align UL timing with the network and/or reconfigure the configured grant for data transmission. Therefore, the wireless device could continue data transmission.

According to some embodiments of the present disclosure, a wireless device may keep running a TAT when the wireless device leaves a connected state with a network. A wireless device may use the TAT for checking validity of a configured grant. When the TAT is expired the wireless device may deactivate the configured grant.

The present disclosure may be applied to various future technologies, such as AI, robots, autonomous-driving/self-driving vehicles, and/or extended reality (XR).

<AI>

AI refers to artificial intelligence and/or the field of studying methodology for making it. Machine learning is a field of studying methodologies that define and solve various problems dealt with in AI. Machine learning may be defined as an algorithm that enhances the performance of a task through a steady experience with any task.

An artificial neural network (ANN) is a model used in machine learning. It can mean a whole model of problem-solving ability, consisting of artificial neurons (nodes) that form a network of synapses. An ANN can be defined by a connection pattern between neurons in different layers, a learning process for updating model parameters, and/or an activation function for generating an output value. An ANN may include an input layer, an output layer, and optionally one or more hidden layers. Each layer may contain one or more neurons, and an ANN may include a synapse that links neurons to neurons. In an ANN, each neuron can output a summation of the activation function for input signals, weights, and deflections input through the synapse. Model parameters are parameters determined through learning, including deflection of neurons and/or weights of synaptic connections. The hyper-parameter means a parameter to be set in the machine learning algorithm before learning, and includes a learning rate, a repetition number, a mini batch size, an initialization function, etc. The objective of the ANN learning can be seen as determining the model parameters that minimize the loss function. The loss function can be used as an index to determine optimal model parameters in learning process of ANN

Machine learning can be divided into supervised learning, unsupervised learning, and reinforcement learning, depending on the learning method. Supervised learning is a method of learning ANN with labels given to learning data. Labels are the answers (or result values) that ANN must infer when learning data is input to ANN. Unsupervised learning can mean a method of learning ANN without labels given to learning data. Reinforcement learning can mean a learning method in which an agent defined in an environment learns to select a behavior and/or sequence of actions that maximizes cumulative compensation in each state.

Machine learning, which is implemented as a deep neural network (DNN) that includes multiple hidden layers among ANN, is also called deep learning. Deep learning is part of machine learning. In the following, machine learning is used to mean deep learning.

<Robot>

A robot can mean a machine that automatically processes or operates a given task by its own abilities. In particular, a robot having a function of recognizing the environment and performing self-determination and operation can be referred to as an intelligent robot. Robots can be classified into industrial, medical, household, military, etc., depending on the purpose and field of use. The robot may include a driving unit including an actuator and/or a motor to perform various physical operations such as moving a robot joint. In addition, the movable robot may include a wheel, a break, a propeller, etc., in a driving unit, and can travel on the ground or fly in the air through the driving unit.

<Autonomous-Driving/Self-Driving>

The autonomous-driving refers to a technique of self-driving, and an autonomous vehicle refers to a vehicle that travels without a user's operation or with a minimum operation of a user. For example, autonomous-driving may include techniques for maintaining a lane while driving, techniques for automatically controlling speed such as adaptive cruise control, techniques for automatically traveling along a predetermined route, and techniques for traveling by setting a route automatically when a destination is set. The autonomous vehicle may include a vehicle having only an internal combustion engine, a hybrid vehicle having an internal combustion engine and an electric motor together, and an electric vehicle having only an electric motor, and may include not only an automobile but also a train, a motorcycle, etc. The autonomous vehicle can be regarded as a robot having an autonomous driving function.

<XR>

XR are collectively referred to as VR, AR, and MR. VR technology provides real-world objects and/or backgrounds only as computer graphic (CG) images, AR technology provides CG images that is virtually created on real object images, and MR technology is a computer graphics technology that mixes and combines virtual objects in the real world. MR technology is similar to AR technology in that it shows real and virtual objects together. However, in the AR technology, the virtual object is used as a complement to the real object, whereas in the MR technology, the virtual object and the real object are used in an equal manner. XR technology can be applied to HMD, head-up display (HUD), mobile phone, tablet PC, laptop, desktop, TV, digital signage. A device to which the XR technology is applied may be referred to as an XR device.

FIG. 12 shows an example of an AI device to which the technical features of the present disclosure can be applied.

The AI device 1200 may be implemented as a stationary device or a mobile device, such as a TV, a projector, a mobile phone, a smartphone, a desktop computer, a notebook, a digital broadcasting terminal, a PDA, a PMP, a navigation device, a tablet PC, a wearable device, a set-top box (STB), a digital multimedia broadcasting (DMB) receiver, a radio, a washing machine, a refrigerator, a digital signage, a robot, a vehicle, etc.

Referring to FIG. 12, the AI device 1200 may include a communication part 1210, an input part 1220, a learning processor 1230, a sensing part 1240, an output part 1250, a memory 1260, and a processor 1270.

The communication part 1210 can transmit and/or receive data to and/or from external devices such as the AI devices and the AI server using wire and/or wireless communication technology. For example, the communication part 1210 can transmit and/or receive sensor information, a user input, a learning model, and a control signal with external devices. The communication technology used by the communication part 1210 may include a global system for mobile communication (GSM), a code division multiple access (CDMA), an LTE/LTE-A, a 5G, a WLAN, a Wi-Fi, Bluetooth™, radio frequency identification (RFID), infrared data association (IrDA), ZigBee, and/or near field communication (NFC).

The input part 1220 can acquire various kinds of data. The input part 1220 may include a camera for inputting a video signal, a microphone for receiving an audio signal, and a user input part for receiving information from a user. A camera and/or a microphone may be treated as a sensor, and a signal obtained from a camera and/or a microphone may be referred to as sensing data and/or sensor information. The input part 1220 can acquire input data to be used when acquiring an output using learning data and a learning model for model learning. The input part 1220 may obtain raw input data, in which case the processor 1270 or the learning processor 1230 may extract input features by preprocessing the input data.

The learning processor 1230 may learn a model composed of an ANN using learning data. The learned ANN can be referred to as a learning model. The learning model can be used to infer result values for new input data rather than learning data, and the inferred values can be used as a basis for determining which actions to perform. The learning processor 1230 may perform AI processing together with the learning processor of the AI server. The learning processor 1230 may include a memory integrated and/or implemented in the AI device 1200. Alternatively, the learning processor 1230 may be implemented using the memory 1260, an external memory directly coupled to the AI device 1200, and/or a memory maintained in an external device.

The sensing part 1240 may acquire at least one of internal information of the AI device 1200, environment information of the AI device 1200, and/or the user information using various sensors. The sensors included in the sensing part 1240 may include a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, an optical sensor, a microphone, a light detection and ranging (LIDAR), and/or a radar.

The output part 1250 may generate an output related to visual, auditory, tactile, etc. The output part 1250 may include a display unit for outputting visual information, a speaker for outputting auditory information, and/or a haptic module for outputting tactile information.

The memory 1260 may store data that supports various functions of the AI device 1200. For example, the memory 1260 may store input data acquired by the input part 1220, learning data, a learning model, a learning history, etc.

The processor 1270 may determine at least one executable operation of the AI device 1200 based on information determined and/or generated using a data analysis algorithm and/or a machine learning algorithm. The processor 1270 may then control the components of the AI device 1200 to perform the determined operation. The processor 1270 may request, retrieve, receive, and/or utilize data in the learning processor 1230 and/or the memory 1260, and may control the components of the AI device 1200 to execute the predicted operation and/or the operation determined to be desirable among the at least one executable operation. The processor 1270 may generate a control signal for controlling the external device, and may transmit the generated control signal to the external device, when the external device needs to be linked to perform the determined operation. The processor 1270 may obtain the intention information for the user input and determine the user's requirements based on the obtained intention information. The processor 1270 may use at least one of a speech-to-text (STT) engine for converting speech input into a text string and/or a natural language processing (NLP) engine for acquiring intention information of a natural language, to obtain the intention information corresponding to the user input. At least one of the STT engine and/or the NLP engine may be configured as an ANN, at least a part of which is learned according to a machine learning algorithm. At least one of the STT engine and/or the NLP engine may be learned by the learning processor 1230 and/or learned by the learning processor of the AI server, and/or learned by their distributed processing. The processor 1270 may collect history information including the operation contents of the AI device 1200 and/or the user's feedback on the operation, etc. The processor 1270 may store the collected history information in the memory 1260 and/or the learning processor 1230, and/or transmit to an external device such as the AI server. The collected history information can be used to update the learning model. The processor 1270 may control at least some of the components of AI device 1200 to drive an application program stored in memory 1260. Furthermore, the processor 1270 may operate two or more of the components included in the AI device 1200 in combination with each other for driving the application program.

FIG. 13 shows an example of an AI system to which the technical features of the present disclosure can be applied.

Referring to FIG. 13, in the AI system, at least one of an AI server 1320, a robot 1310 a, an autonomous vehicle 1310 b, an XR device 1310 c, a smartphone 1310 d and/or a home appliance 1310 e is connected to a cloud network 1300. The robot 1310 a, the autonomous vehicle 1310 b, the XR device 1310 c, the smartphone 1310 d, and/or the home appliance 1310 e to which the AI technology is applied may be referred to as AI devices 1310 a to 1310 e.

The cloud network 1300 may refer to a network that forms part of a cloud computing infrastructure and/or resides in a cloud computing infrastructure. The cloud network 1300 may be configured using a 3G network, a 4G or LTE network, and/or a 5G network. That is, each of the devices 1310 a to 1310 e and 1320 consisting the AI system may be connected to each other through the cloud network 1300. In particular, each of the devices 1310 a to 1310 e and 1320 may communicate with each other through a base station, but may directly communicate with each other without using a base station.

The AI server 1320 may include a server for performing AI processing and a server for performing operations on big data. The AI server 1320 is connected to at least one or more of AI devices constituting the AI system, i.e. the robot 1310 a, the autonomous vehicle 1310 b, the XR device 1310 c, the smartphone 1310 d and/or the home appliance 1310 e through the cloud network 1300, and may assist at least some AI processing of the connected AI devices 1310 a to 1310 e. The AI server 1320 can learn the ANN according to the machine learning algorithm on behalf of the AI devices 1310 a to 1310 e, and can directly store the learning models and/or transmit them to the AI devices 1310 a to 1310 e. The AI server 1320 may receive the input data from the AI devices 1310 a to 1310 e, infer the result value with respect to the received input data using the learning model, generate a response and/or a control command based on the inferred result value, and transmit the generated data to the AI devices 1310 a to 1310 e. Alternatively, the AI devices 1310 a to 1310 e may directly infer a result value for the input data using a learning model, and generate a response and/or a control command based on the inferred result value.

Various embodiments of the AI devices 1310 a to 1310 e to which the technical features of the present disclosure can be applied will be described. The AI devices 1310 a to 1310 e shown in FIG. 13 can be seen as specific embodiments of the AI device 1200 shown in FIG. 12.

In view of the exemplary systems described herein, methodologies that may be implemented in accordance with the disclosed subject matter have been described with reference to several flow diagrams. While for purposed of simplicity, the methodologies are shown and described as a series of steps or blocks, it is to be understood and appreciated that the claimed subject matter is not limited by the order of the steps or blocks, as some steps may occur in different orders or concurrently with other steps from what is depicted and described herein. Moreover, one skilled in the art would understand that the steps illustrated in the flow diagram are not exclusive and other steps may be included or one or more of the steps in the example flow diagram may be deleted without affecting the scope of the present disclosure.

Claims in the present description can be combined in a various way. For instance, technical features in method claims of the present description can be combined to be implemented or performed in an apparatus, and technical features in apparatus claims can be combined to be implemented or performed in a method. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in an apparatus. Further, technical features in method claim(s) and apparatus claim(s) can be combined to be implemented or performed in a method. Other implementations are within the scope of the following claims. 

What is claimed is:
 1. A method performed by a wireless device in a wireless communication system, the method comprising: receiving, from a network, a Radio Resource Control (RRC) Connection Release message including a Preconfigured Uplink Resource (PUR) configuration, wherein the PUR configuration includes (i) information on a Time Alignment (TA) timer for a PUR, and (ii) information on an identity related to the PUR configuration; starting the TA timer; and leaving RRC_CONNECTED upon receiving the RRC Connection Release message; based on (i) the TA timer running and (ii) a data size for transmission being smaller than or equal to a maximum size for the PUR: initiating transmission using the PUR; based on (i) the TA timer being expired or (ii) a data size for transmission being greater than a maximum size for the PUR: transmitting an RRC Connection Request message to the network; and releasing the PUR configuration.
 2. The method of claim 1, wherein the PUR is a resource of a Semi-Persistent Scheduling configuration or a configured grant.
 3. The method of claim 1, wherein the configuration includes the maximum size for the PUR.
 4. The method of claim 1, wherein the method further comprises, while in leaving RRC_CONNECTED: selecting a cell on the network; and camping on the cell.
 5. The method of claim 1, wherein the method further comprises, deactivating the PUR configuration when the TAT is expired.
 6. The method of claim 1, wherein the wireless device is an autonomous driving apparatus in communication with at least one of a mobile terminal, a network, and/or autonomous vehicles other than the wireless device.
 7. A wireless device in a wireless communication system, the wireless device comprising: a memory; a transceiver; and a processor, operably coupled to the memory and the transceiver, and configured to: control the transceiver to receive, from a network, a Radio Resource Control (RRC) Connection Release message including a Preconfigured Uplink Resource (PUR) configuration, wherein the PUR configuration includes (i) information on a Time Alignment (TA) timer for a PUR, and (ii) information on an identity related to the PUR configuration; start the TA timer; and leave RRC_CONNECTED upon receiving the RRC Connection Release message; based on (i) the TA timer running and (ii) a data size for transmission being smaller than or equal to a maximum size for the PUR: initiate transmission using the PUR; based on (i) the TA timer being expired or (ii) a data size for transmission being greater than a maximum size for the PUR: control the transceiver to transmit an RRC Connection Request message to the network; and release the PUR configuration.
 8. A processor for a wireless device in a wireless communication system, wherein the processor is configured to control the wireless device to perform operations comprising: receiving, from a network, a Radio Resource Control (RRC) Connection Release message including a Preconfigured Uplink Resource (PUR) configuration, wherein the PUR configuration includes (i) information on a Time Alignment (TA) timer for a PUR, and (ii) information on an identity related to the PUR configuration; starting the TA timer; and leaving RRC_CONNECTED upon receiving the RRC Connection Release message; based on (i) the TA timer running and (ii) a data size for transmission being smaller than or equal to a maximum size for the PUR: initiating transmission using the PUR; based on (i) the TA timer being expired or (ii) a data size for transmission being greater than a maximum size for the PUR: transmitting an RRC Connection Request message to the network; and releasing the PUR configuration. 